O. I. Malov

Flux densities of 235 pulsars at 102.5 MHz

The flux densities of 235 mostly faint pulsars at 102.5 MHz are presented. The observations were carried out on the very sensitive Large Phased Array of the Lebedev Institute of Physics in 1994–1998. The procedure used for the observations and data processing is described in detail, and estimates of probable errors, including the effect of interstellar scintillations, are given. The mean spectral indices at 102–408 MHz for normal and millisecond pulsars are calculated and compared with information from higher frequency data. There is a deficit of pulsars at distances of less than 3 kpc.

Radio emission from two anomalous X-ray pulsars

Observations of the anomalous X-ray pulsar (AXP) 1E 2259+586 and the AXP candidate 1RXS J1308.6+212708 at 111, 87, and 61 MHz are reported. The observations were carried out on two high-sensitivity radio telescopes of the Pushchino Radio Astronomy Observatory. Mean pulse profiles are presented, and the dispersion measures, distances, spectral indices, and integrated radio luminosities of both objects are estimated. Comparison with X-ray data shows large differences in the mean pulse widths and luminosities. The detection of radio emission from these two AXPs, together with other data, suggests the need to revise the radio-emission mechanisms in the magnetar model or the magnetar model itself.

Average pulse profiles of radio pulsars at 102 and 111 MHz

Average profiles for 180, mostly faint, pulsars at 102 and 111 MHz are presented. Pulse shapes have been obtained for the first time for most of the faint pulsars (about 50% of the total sample). A comparison with high-frequency data (mostly at 234, 408, 610, 925, and 1408 MHz) demonstrates appreciable changes in the profile width and shape with frequency. For most pulsars, the number of components is preserved, but the intensities of individual components can change. As a rule, the profile width increases with decreasing frequency. The possible generation of emission at the cyclotron frequencies is considered.

Detection of radio emission from the AXP 4U 0142+61

AbstractThe detection of pulsed radio emission from the X-ray pulsar AXP 4U 0142+61 with a period of P = 8.68832935(6) s and a period derivative of

The radio pulsar J0205+6449 in the supernova remnant 3C 58

\dot P

The unusual profile of the radio pulsar Geminga

= 18.713(4) × 10−13 s/s is reported. The observations were carried out on two high-sensitivity radio telescopes of the Pushchino Radio Astronomy Observatory: the Large Phased Array at 111MHz and the DKR-1000 at 40MHz.Mean pulse profiles are presented; the measured flux density is S111 = 30 ± 20 mJy. The estimated distance derived from the dispersion measure, 27 pc/cm3, is 1.4 kpc, and the integrated radio luminosity is LR = 1.5 × 1027 erg/cm. Comparison with X-ray data shows an appreciable difference in the pulse duration (the radio pulse is about a factor of 20 more narrow) and strong variations in the flux density.

Studies of weak compact radio sources

The integrated radio luminosities of 311 long-period (P > 0.1 s) and 27 short-period (P < 0.1 s) pulsars have been calculated using a new compilation of radio spectra. The luminosities are in the range 1027 − 1030 erg/s for 88% of the long-period pulsars and 1028 − 1031 erg/s for 88% of the short-period pulsars. We find a high correlation between the luminosity L and the estimate L1 = S400d2 from the catalog of Taylor et al. The factor η for the transformation of the rotational energy of the neutron star into radio emission increases-decreases with increasing period for long-period and short-period pulsars. The mean value of η is −3.73 for the long-period and −4.85 for short-period pulsars. No dependence was found between L and the pulsar’s kinematic age tk = |z|/〈vz〉, where |z| and 〈vz〉 = 300 km/s are the pulsars’ height above the plane of the Galaxy and mean velocity. A dependence of L on the rate of rotational energy losses Ė was found for both groups of pulsars. It is shown that L ∝ Ė1/3 for the entire sample. The pulsar luminosity function is constructed, and the total number and birth rate of pulsars in the Galaxy are calculated.

Radio emission from AXP and XDINS

AbstractThe detection of pulsed radio emission from the recently discovered X-ray pulsar J0205+6449 in the young supernova remnant 3C 58 is reported together with the results of first studies of this emission. The observations were carried out at 111 and 88 MHz on radio telescopes of the Pushchino Observatory. The pulsar period, 65.68 ms, and period derivative,